This project is investigating the role of sensory processes and oculomotor tonus in the control of visual accommodation and binocular vergence. The efficiency of these responses varies widely across viewing conditions and individuals. In many situations, accommodation and vergence adjustments are biased toward the individual's characteristic resting (tonus) states, resulting in anomalous refractive errors and fixation disparity which can seriously interfere with normal perception and performance. In addition, recent evidence indicates that near work can modify the resting tonus and response characteristics of accommodation and vergence, and suggests that these changes may contribute to asthenopia and the development of myopia. Unobtrusive techniques, such as laser optometry and photorefraction, are being used to study (1) specific variables which modulate the resting tonus of accommodation and vergence; (2) the role of contrast sensitivity and binocular sensory integration in controlling accommodation; and (3) the nature of developmental changes in the sensory control of accommodation. The results of this research should enhance our understanding of the central mechanisms participating in oculomotor control and their influence on visual performance. They may also provide new clues to the role of accommodation and vergence in disorders such as strabismus, amblyopia, myopia, and asthenopia.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY003898-05
Application #
3258372
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1982-01-01
Project End
1990-06-30
Budget Start
1986-07-01
Budget End
1987-06-30
Support Year
5
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Franklin and Marshall College
Department
Type
Schools of Arts and Sciences
DUNS #
069773646
City
Lancaster
State
PA
Country
United States
Zip Code
17604
Francis, Ellie L; Jiang, Bai-chuan; Owens, D Alfred et al. (2003) Accommodation and vergence require effort-to-see. Optom Vis Sci 80:467-73
Owens, D A; Tyrrell, R A (1992) Lateral phoria at distance: contributions of accommodation. Invest Ophthalmol Vis Sci 33:2733-43
Heuer, H; Owens, D A (1989) Vertical gaze direction and the resting posture of the eyes. Perception 18:363-77
Owens, D A; Wolf-Kelly, K (1987) Near work, visual fatigue, and variations of oculomotor tonus. Invest Ophthalmol Vis Sci 28:743-9
Owens, D A (1986) Oculomotor tonus and visual adaptation. Acta Psychol (Amst) 63:213-31